I've been playing around with this too. My issue is that I have 1000's of MP3 but I keep them on an external HD. But I wish to create playlists on the existing files I have on my YP-U2J. I've had the most luck using Winamp, It will create a playlist, however when I restart winamp or re-plug in the device, it will not display the playlists on the YP-U2J. Its annoying.